1. Field of the Invention
This invention relates to an inline type pump in which a flow passage is formed within a motor having a stator and a rotor as its main component parts.
2. Description of the Prior Art
As already described in the gazette of Japanese Patent Laid-Open No. Hei 10-246193 or the gazette of Japanese Patent Laid-Open No. Hei 1-230088, for example, this kind of inline type pump is constructed such that the rotor installed inside the stator has a function of an axial flow vane by forming both some protrusions and some recesses at its outer circumference, and the rotor is rotated to cause fluid sucked at a suction port of one end side of the rotor to be discharged out of a discharging port at the other end of the rotor.
In such an inline type pump as described above, a rotational kinetic energy is given to fluid by the axial flow vane, and the kinetic energy is lost as a frictional loss at the wall of an inner circumference or the discharging port or an eddy loss caused by turbulent flow while the kinetic energy is not converted into a static pressure energy, thereafter the energy is transferred, so that the pump shows a poor efficiency.
In addition, since the fluid always flows only in one axial direction of the rotor, a reacting pressure of the fluid may act against the rotor as a thrust load and it shows a problem that a life of the bearing becomes quite short.
It is an object of the present invention to provide an inline type pump in which a fluid supplying efficiency can be increased while a small-sized structure is satisfactorily attained.
The present invention is applied to an inline type pump in which the rotor having an axial flow vane for axially feeding out fluid sucked from the suction port toward the discharging port is rotatably arranged inside the cylindrical stator. There is provided a pressure chamber in which a rotational kinetic energy of the fluid sent toward the discharging port is converted into a static pressure energy by the axial flow vane of the rotor, and when the rotor is rotated, the fluid sucked from the suction port is transferred to the pressure chamber by the axial flow vane, the rotational kinetic energy is converted into the static pressure energy at this pressure chamber and then the fluid is discharged out of the discharging port.